Return to Castle Shadowcrag is an adventure for 10th to 11th level characters. The open content includes the monster stat blocks, trap mechanics, and new magic items.
OGL Content:
Black Tapestry, Animated Object - (monster)
Bone Swarm - (monster)
Dark Eye - (monster)
Devil, Horned - (monster)
Glimmerspike - (item)
Glyph of Warding - Explosive Runes - (trap)
Golem, Stained Glass - (monster)
Hallow Trap - (trap)
Hound of The Night - (monster)
Margoyle - (monster)
Phase Spider - (monster)
Rapier of Speed - (item)
Shadow Beast - (monster)
Shadow Fey Rider - (monster)
Shadow, Greater - (monster)
Spectral Guardian - (monster)
Sword of Bright Shadows - (item)
Throne of Past Lords - (trap)